A feature offered within infrastructure-based communications systems is group communication. Traditionally, group communication was mainly available within Professional Radio or Private Mobile Radio (PMR) systems, such as TETRA (TErrestrial Trunked RAdio), many of which were designed for professional and governmental users, such as personnel from police, military forces, oil plants, and the like.
Group communication with a “push-to-talk, release-to-listen” (PTT) feature is another widely used feature in PMR systems. Generally, in group voice communication with a PTT feature, a group call is based on the use of a pressel (or push-to-talk button) as a switch on a subscriber unit. By pressing the pressel, the user indicates his/her desire to speak to a specific subscriber group, and the subscriber equipment sends a service request to a corresponding communication network. The communication network either rejects the request or allocates the requested resources on the basis of predetermined criteria, such as availability of resources, priority of the requesting user, etc. At the same time, a connection is also established with other users in the subscriber group. After a voice connection is established, the requesting user can talk, and the other users can listen on the channel or vice versa.
Group communication both with and without the PTT feature is becoming readily available in public infrastructure-based communications systems, and a demand for such services continues to increase. Further, group communication is no longer limited to voice communication but has also been extended to sharing other media. However, during a multimedia group call, the existing infrastructure-based communication systems use centralized equipment such as a centralized controller to distribute the media to each of the intended receivers.
Such distribution of media for a group call can require a significantly high amount of radio frequency resources, essentially becoming a limiting factor in the number of participants in a communication group. This extensive use of the radio frequency resources for distributing the media by the controller increases the probability of failures in the media transfer for a variety of reasons such as network congestion, malfunctioning of the source and destination hardware and/or software, etc. This problem is much more prominent when the group members are present in a close geographical proximity. Accordingly, there is a need for an improved method for distributing media in an infrastructure-based communication system.
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Apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the various embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Thus, it will be appreciated that for simplicity and clarity of illustration, common and well-understood elements that are useful or necessary in a commercially feasible embodiment may not be depicted in order to facilitate a less obstructed view of these various embodiments.